This disclosure relates in general to controlling replaceable modules in a printing system, such as a digital printing apparatus. More specifically, the invention relates to a computerized method and system for validating and differentiating between consumables in such a printing environment where the replaceable module provides an accessible unique identifier.
Many machines have replaceable sub-assemblies. These subassemblies may be arranged as unit called a cartridge, and if intended for replacement by the customer or machine owner, may be referred to as a customer replaceable unit (CRU). Examples of a CRU may include printer cartridge, toner cartridge, transfer assembly unit, photo conductive imaging unit, transfer roller, fuser or drum oil unit, and the like. It may be desirable for a CRU design to vary over the course of time due to manufacturing changes or to solve post-launch problems with either the machine, the CRU, or a CRU and machine interaction. It is known to provide the CRU with a monitoring device commonly referred to as a CRUM (Customer Replaceable Unit Monitor). A CRUM is typically a memory device, such as a ROM, EEPROM, SRAM, or other suitable non-volatile memory device, provided in or on the cartridge. Information identifying the CRU is written on the EEPROM during manufacture of the CRUM. For example, information identifying a CRU as a developer cartridge and identifying the type of carrier, developer, and transfer mechanism contained in the developer cartridge may be written in the memory contained in the CRUM. When a CRU containing such a CRUM is installed in a machine, the machine's control unit reads the identifying information stored in the CRUM.
It is also important to ensure that CRUs (Customer Replaceable Units) are authentic and meet the original equipment manufacturer's (OEM) operational specifications. Imaging devices such as printers may be programmed to function differently in different markets even though the hardware is identical. Actions such as reconfiguring or copying electronic chip based identification creates significant problems affecting not only the profits of the manufacturer but also legitimate resellers as well as entailing product functionality risks and reduced image quality for the customer. Poor quality counterfeiting may also present customers with health and safety risks extending from materials used and inadequate containment of fine toner dust, for example. Likewise using a CRU beyond its useful life may have a detrimental effect on print quality and/or on machine components. In some instances, it is desirable to determine whether a machine, especially the CRU, is being operated in accordance to contractual obligations such as warranty or licenses.
One early technique to authenticate CRUs relied on keyed shapes of the consumable. Such keyed shapes can be designed so that only a consumable in the keyed shape will fit into a given type of host. As an example, an ink jet printer can be adapted to receive only refill ink cartridges having a particular keyed shape. The use of such a keyed shape can prevent interchange of consumables between different types of host. That approach is generally ineffective for authentication, however, because the keyed shape of the consumable can be readily observed and easily duplicated.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for validating and authenticating a customer releasable unit.